IrNo QuaLirv oJ Ltre' Po Box t*'tl!ioolt;;,1;,',!:,,1;i;yi,!:ri:';,2n,niver'sirt'rtJ Meta';*icttr' Po tso'r 6t6' Risk factors for diet-r'elated disorders are oxiclative stress and chlonic intlarnmation. Wheat is a source of phytochernicals with antioxiclant activity that might play a role in the observed protection of whole-grain diets against metabolic disorders The aims of the present study were first to investigate the bioaccessibility of antioxidant and anti-inflammatory activity t'om difterent wheat fractiolls during gastrointestinal (Gl) transit and second to demonstrate the contribution of wheat cornpounds to these health factors Experiments were perforned in the TIM system, which is a dynamic computer'-controlled model consisting of gastric, duodenal, je.lunal and ileal colnpartlnents simulating conditions in the human GI tract(r'2). Samples were collected in I h aliquots tbr 6h fionr the dialysates of the jejunal and ileal colnpartlnents to measure the kinetics of bioaccessibility of antioxidant capacity and anti-inflanrnl?rtory responses. Antioxidant capacity (Trolox equivalent antioxidant capacity assay) and ferulic acid, polyphenol and prorein conterits were de[ennined. Anti-inflanrmatory effects were measured in extmcts and TIM samples nsing a hunran rnacroplrage cell systenl with lipopolysirccharide (LPS)-induced TNFa and IL-6 secretion. Antioxidant capacity was unevenly distlibuted within the whear fractions (aleurone ti'actions>bran tiactions>flour fractions), without difTerences between cultivars (Tiger and Crousty). Antioxidant capacity was conelated rvith the f-erulic acid content (/l 0.9(r, P<0.00001) Ferulic acid was the rnajor contributor to the antioxidant capacity in bran and aleurone fi'actions (-50-607c). However, fÞr'ulic acid did not reduce TNFo and IL-6 levels in a dose-dependent lnanner. The TIM experirnents showed that the antioxidant capacity was bioaccessible during CI digestion. [n the case of the blan and aleurone fi'actions the bioaccessibility was significantly lower (20-30a/o initial aritioxiclant capacity) than that frorn the flour fraction. The bioaccessibility of ferulic acid was sirnilarly low fronr the bran ancl aleurone fractions. In experiments with flour terulic acid was below the detection limit in the dialysate sarnples, because of the low initial level ât oml intake The dialysates samples collected from TlM showed reduced levels of TNFq, for the bran and aleurone fi'actions, reaching nraxirnal inhibition at the 2nd hour and 3rd hour (Figure). These data corresponded with the maxirnuin levels of the bioaccessibility ol the antioxidant capacity from these fractions.